C rated vs E rated

[Horosha]

Hi,
Can one advise me for the choice of my new tires for my hilux revo.
I would like to give a try on the cooper st maxx and go for the 255/75/R17 - but these have a C rated load index. I think with the E rated 255/80 to many modifications have to be made.
I do 40% highway 60% gravel and rocky trails loaded with standard camping equipment, fridge, ground tent, ...(so no RTT, drawers, steel bumpers...).
Will a C rated tire do the job.

pro/contra

Thx.

 

[Louiston]

That would depend on the loaded weight of your truck.

 

[rho]

I prefer E rated tires, they tend to hold up better and get flats/cuts less in my experience. The difference in ride is big, esp on something light like my jeep.

 

[Trail_pilot]

I prefer C rated on my Jeep but it is relatively light .. maybe 4500lb fully loaded. I also air down low ( 8psi) because I do more technical trails where I am doing more rock crawling than moving fast. I run them about 27 psi on the road but it is also no my daily driver. I had E rated tires previously and found I needed to air down more than I really wanted to on the trails.

 

[JCWages]

If the C rated tire will meet the load demands of your setup then it would generally be the prefered choice for ride quality and traction (conforms to terrain better when aired down. Assuming the sidewall plies don't change between the two load rating then both will be strong. A LOT of the large flotation sized mud terrains (35" to 40") used by rock crawlers are load range C and D. Mid-sized trucks generally don't need an E tire and by the time they do they are seriously over GVWR. I wish there were more C options in the tire size I run but I'm stuck with Es for the tires I prefer.

 

[Louiston]

C are rated at 6 ply
E are rated at 10 ply

This is for LT (light truck) tires.

 

[JCWages]

C are rated at 6 ply
E are rated at 10 ply

This is for LT (light truck) tires.

Right but sidewall plies are a different measure. Most are 2ply regardless of load rating until you get into mud terrain and rough terrain (R/T or Hybrids) which are mostly 3ply. There are a few ATs with 3ply as well. So you definitely have to take that into consideration. :)

 

[Louiston]

Right but sidewall plies are a different measure. Most are 2ply regardless of load rating until you get into mud terrain and rough terrain (R/T or Hybrids) which are mostly 3ply. There are a few ATs with 3ply as well. So you definitely have to take that into consideration. :)

Yeah, I think he would want a 3ply sidewall (KO2 for example) being he mentioned 60% off road rocky trails.

 

[JCWages]

Yeah, I think he would want a 3ply sidewall (KO2 for example) being he mentioned 60% off road rocky trails.

Agreed. ST Maxx, KO2, Geolandar X-AT, Kenda Klever R/T are all good options.

 

[Billiebob]

for my hilux revo.
I would like to give a try on the cooper st maxx and go for the 255/75/R17 - but these have a C rated load index.

Which is exactly what the hilux needs.

Basically,
C is for light, 1/2 ton trucks
D is for 3/4 ton truck capacity
E is for 1 ton and dually loading

Not that you cannot use the heavier tire but they are heavier and stiffer and your ride will be stiffer and harsher.
And that stiffer sidewall will distort less if you air down. The C rated tire will give better, more compliant floatation aired down.
We had a truck tire on a Datsun, even flat the tire did not distort.

 

[Dilldog]

Honestly rubber compound has just as much if not more to do with puncture resistance than anything. Just about any off road tire will be made with high abrasion resistant rubber compound that will also be good at resisting cutting and punctures. Naturally everything has its limits though. Higher load rating tires do tend to be more durable just by virtue of having more material there, but for a specific use sometimes that is not always whats best. Sidewall flex and ride quality are not the only things to worry about also. A higher load rating tire will be heavier, thus putting more strain on suspension, brakes, and drive train. Often its hardly worth mentioning, but when you go off road while loaded down you really do need to consider everything to ensure longevity of your rig. Your goal really should be getting a tire that is rated closely (but never under) to 1/2 of your heaviest axles gross weight.

 

[MidOH]

You can't put D's on a ''3/4 ton'' truck. My ''3/4 ton truck'' has more than 1.5 tons cargo capacity. D's will just melt and fall off of my wheels. You can put D's on an F150.......maybe. I've literally melted the tread off of countless E rated tires.

I'd go with E's. 265/70r17 Cooper STT Pro's appear to be almost exactly the same size as the 255's you listed. As long as your wheel is 7.5" wide, you should be fine.

Sometimes tire design is equal. You might want to email Cooper. For example the D rated 37x13.5r18 Cooper STT is exactly the same construction as the E rated 35x12.5r18. But the 37 melts and explodes rolling your truck and camper over, on death hwy into a crowd of tourists. So it gets derated because of such. Giant mud terrain with chunky knobs, extra hot pavement, and heavy camper or trailers, don't mix.

 

[yeos]

Yeah, I think he would want a 3ply sidewall (KO2 for example) being he mentioned 60% off road rocky trails.

One thing to keep in mind. Only the D and E rated KO2s have three ply sidewalls as far as I know.

 

[Louiston]

One thing to keep in mind. Only the D and E rated KO2s have three ply sidewalls as far as I know.

Yeah, I know ....
I use E rated KO2's on my FJ. Factory spec on the Trail Teams version. For the rocky terrain I use my truck in, I wouldn't want a lesser tire.

 

[Daryl 32]

Our 1999 3/4 ton is spec-ed to run E rated tires. And all of the E rated tires I have bought have been 3 ply side walls. My son runs E rated tires on his 06 Tacoma regular cab long bed, and likes them a lot.

He runs 35 psi on the highway and can go down to as low as 12 psi off road if needed. I run 80 psi "what they are rated at" on our F250 on road and went down as low as 25 psi on our last trip, which was Baja California. With the truck weighing in at about 8,700 lb on that trip, 25 psi was the lowest I felt comfortable with not wanting to pop one off the bead. The tires on the F250 are Cooper Discovery A/T2's.



Side note with about 250 miles of rocky off road trails no one had a flat. Our daughter and son in law run D rated tires on their 06 F150.

Running a higher rated tire then the vehicle calls for when you off road is not a bad thing to do.

 

[Seanm26]

Running a higher load rated tire on a really light vehicle is like running premium gas in an engine designed for 87 octane. You can, but it isn't really doing anything.

Most E tires have a load index of 121, meaning they can carry over 3200 lbs per tire. My Mitsubishi has a curb weight right now of 4100 lbs. Factory recommened tire pressure is 26 psi. E rated tires would be a waste of money for me.

 

[Daryl 32]

Sean what you bring up is true - but if I understand the OP question, he is asking more about durability of a tire off road on gravel roads. Also if it is a fully outfitted overland rig and has beefed up suspension then higher rated tires cannot hurt.

Just thinking out load hear.

 

[Seanm26]

Like said earlier, a higher rated tire doesn't mean it is more resistant to puncture.

 

[Louiston]

3 ply sidewalls versus 2 ply sidewalls, 3 ply are absolutely stronger.

You can believe whatever you like.

 

[slomatt]

Interesting discussion, especially since I need new tires on both my trucks. :)

In my experience tire failures on the trail are extremely uncommon. In 20 years of offroading I can think of one, and in that case it was a large branch straight through a sidewall. All of my tire problems have been nails and other crap (half a pair of pliers) picked up on paved roads. I've always run C rated tires on my trucks and have never had a failure on the trail, perhaps I've just been lucky.

Anybody else had first hand experience with on-trail failures? If so, do you happen to know the load rating of the tire?